Antibiofilm Nitric Oxide-Releasing Polydopamine Coatings

Abstract

The growing number of patient morbidity related to nosocomial infections has placed an importance on the development of new antibacterial coatings for medical devices. Here, we utilize the versatile adhesion property of polydopamine (pDA) to design an antibacterial coating that possesses low-fouling and nitric oxide (NO)-releasing capabilities. To demonstrate this, glass substrates were functionalized with pDA via immersion in alkaline aqueous solution containing dopamine, followed by grafting of low-fouling polymer (poly­(ethylene glycol) (PEG)) via Michael addition and subsequent formation of N-diazeniumdiolate functionalities (NO precursors) by purging with NO gas. X-ray photoelectron spectroscopy confirmed the successful grafting of PEG and formation of N-diazeniumdiolate on polydopamine-coated substrates. NO release from the coating was observed over 2 days, and NO loading is tunable by the pDA film thickness. The antibacterial efficiency of the coatings was assessed using Gram-negative Pseudomonas aeruginosa (i.e., wild-type PAO1 and multidrug-resistant PA37) and Gram-positive Staphylococcus aureus (ATCC 29213). The NO-releasing PEGylated pDA film inhibited biofilm attachment by 96 and 70% after exposure to bacterial culture solution for 24 and 36 h, respectively. In contrast, films that do not contain NO failed to prevent biofilm formation on the surfaces at these time points. Furthermore, this coating also showed 99.9, 97, and 99% killing efficiencies against surface-attached PAO1, PA37, and S. aureus bacteria. Overall, the combination of low-fouling PEG and antibacterial activity of NO in pDA films makes this coating a potential therapeutic option to inhibit biofilm formation on medical devices.

Nitric Oxide-Releasing Polymeric Materials for Antimicrobial Applications: A Review

“…Before biofilm formation, the primary task of a surface (especially used for medical devices) is to inhibit microbial adhesion, thus preventing biofilm formation. Super-hydrophobic polymer coated surfaces [100] and low-fouling polymer coated surfaces [99] have been prepared by several researchers which showed prevention of bacterial adhesion to some extent, and modifying these surfaces with NO releasing functional groups can effectively enhance inhibition of bacterial adhesion. Once biofilms are formed, NO releasing nanoparticles [56,103,104] can serve as antimicrobial agents to disperse biofilms and kill bacteria and are usually more efficient than conventional antibacterial agents.…”

Recent Advances in Surface Nanoengineering for Biofilm Prevention and Control. Part II: Active, Combined Active and Passive, and Smart Bacteria-Responsive Antibiofilm Nanocoatings

“…Similarly, the peptide DJK-5 alone or mixed with EDTA increases the antibiofilm activity of root canal irrigants such as sodium hypochlorite in endodontic therapy [78]. Recently, Sadrearhami et al [72] took advantage of the unique adhesive ability of PDA to nicely use a PDA-coated glass substrate as a versatile scaffold for subsequent surface functionalization by grafting of low-fouling polymer (PEGylation) and introduction of N-diazeniumdiolate moieties as NO precursors. PDA is rich in quinoide and indoline species (Scheme 6).…”

Polydopamine-based nanoreactors: synthesis and applications in bioscience and energy materials

“…[65][66][67][68][69][70][71][72][73] In addition to the aforementioned conventional antibacterial agents, nitric oxide (NO), an endogenously produced molecule, exhibits more efficient antibacterial effects against both Gram-positive and Gram-negative bacteria species by inducing oxidative stress or nitrosative stress. Hollow PDA nanoparticles, 74 PDA-coated iron oxide nanoparticles, 75 and poly(ethylene glycol) grafted PDA coating layers 76 were functionalized with NO precursors/donors (N-diazeniumdiolate) to enhance antibacterial properties. Hence, using PDA as a NO carrier has opened up new opportunities in effective NO delivery and biofilm treatment.…”